I copied Rob on my last message and hope that he enters the conversation.
I haven't measured any of this; I'm just quoting what Rob has told us.
On the ability to send good CW in the presence of latency, it also depends
on what is generating the tone that you are listening to. When we measured
this back in the 1970s, we were using a Drake C line and actually listening
to the transmitted signal. When we built our time sequencers for the
external keyer so that the L4B could be keyed before the T4XC, we played
with variable latency and that's when we noticed that 25mS was pretty much
the border or rather limit where the latency begin to bother the OP.
Of course if the sidetone generated by the radio is in real time, or less
than 25mS latency, then latency of the radio probably won't bother the op.
In our case, we were listening to a signal that was delayed by the amount of
TXD we inserted. This was in the late 70s so I'm struggling to remember
exact details, but Thomas (DL7AV) wrote it up in our magazine and I still
have the article - of course it's in German.
73 - Rick, DJ0IP
(Nr. Frankfurt, Germany)
-----Original Message-----
From: TenTec [mailto:tentec-bounces@contesting.com] On Behalf Of Barry N1EU
Sent: Monday, December 07, 2015 2:59 PM
To: Discussion of Ten-Tec Equipment
Subject: Re: [TenTec] TenTec Digest, Vol 156, Issue 4
I'm not sure that's the right question to ask because recovery doesn't
necessarily happen in real time. The Flex T/R cw recovery is really a mind
blower for an SDR. But does it necessarily mean you can do actual QSK and
hear someone else trying to break you in real time? I think there's still
receive latency so that even with the receiver recovering, it still lags
real time signals by 150msec (or whatever).
Barry N1EU
On Mon, Dec 7, 2015 at 8:50 AM, rick@dj0ip.de <Rick@dj0ip.de> wrote:
> Paul, when you release the PTT and the green line drops, how long does
> it take for the receiver to recover?
>
> 73 - Rick, DJ0IP
> (Nr. Frankfurt, Germany)
>
>
>
> -----Original Message-----
> From: TenTec [mailto:tentec-bounces@contesting.com] On Behalf Of Paul
> Christensen
> Sent: Monday, December 07, 2015 2:38 PM
> To: 'Discussion of Ten-Tec Equipment'
> Subject: Re: [TenTec] TenTec Digest, Vol 156, Issue 4
>
> > Sorry Barry, latency measured on the Anan does not necessarily apply
> > to
> the FLEX 6000.
>
> I made timing and latency measurements of my Flex 6700 using an
> Agilent 4-channel DSO. I captured the data and uploaded the DSO graphic
images.
> Keep an eye on the PTT trace from the external keyer as the timing
> reference. QSK performance has improved further since the date of these
> measurements. QSK performance is at least as good as the K3 and the many
> Ten Tecs I've owned. It is fast. At 40+ wpm, I don't feel like I'm
> dragging characters behind me due to any latency, and there are no
> headphone audio thumps or clicks in CW T/R transitions.
>
>
> https://community.flexradio.com/flexradio/topics/flex_6700_cw_keying_v
> _elecr
> aft_k3
>
> Paul, W9AC
>
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